<template>
  <div class="todo-footer" v-if="total">
    <label>
      <input type="checkbox" v-model="isAll" />
    </label>
    <span>
      <!-- 计算属性显示已完成事件 -->
      <span>已完成{{ doneTotal }}</span> / 全部{{ total }}}
    </span>
    <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  // eslint-disable-next-line vue/multi-word-component-names
  name: 'MyFooter',
  // 获取来自父组件App的事假toods
  props: ['todos'],
  methods: {
    // changeAll(e) {
    //   this.checkAllTodo(e.target.checked)
    // }
    clearAll() {
      if (confirm('确定删除所有已完成事件吗？')) {
        // this.clearAllTodo()
        this.$emit('clearAllTodo')
      }
    }
  },
  computed: {
    // eslint-disable-next-line vue/return-in-computed-property
    doneTotal() {
      // 简易写法
      // let i = 0
      // this.todos.forEach(todo => {
      //   if (todo.done) i++
      // })
      // return i
      return this.todos.reduce((pre, current) => pre + (current.done ? 1 : 0), 0)
    },
    // eslint-disable-next-line vue/return-in-computed-property
    total() {
      return this.todos.length
    },
    isAll: {
      get() {
        return this.doneTotal === this.total && this.total > 0
      },
      set(value) {
        // this.checkAllTodo(value)
        this.$emit('checkAllTodo', value)
      }
    }
  }
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>
